Terminal and control method thereof in wireless communication system

ABSTRACT

The present disclosure relates to a 5G or pre-5G communication system for supporting higher data transfer rates than that of a beyond 4G communication system such as LTE. A control method of a terminal in a wireless communication system, according to an embodiment of the present invention, may comprise the steps of: receiving radio resource control signaling (RRC signaling) for a signal measured by a terminal; identifying a transmission interval of a signal measured by the terminal, on the basis of the received RRC signaling; identifying first information for forming a predetermined beam; and determining whether to change the first information for forming a beam to second information for forming a beam, on the basis of the identified transmission interval.

PRIORITY

This application is a National Phase Entry of PCT InternationalApplication No. PCT/KR2019/004369 which was filed on Apr. 11, 2019, andclaims priority to Korean Patent Application No. 10-2018-0042726, whichwas filed on Apr. 12, 2018, the content of each of which is incorporatedherein by reference.

TECHNICAL FIELD

The disclosure relates to a wireless communication system and, moreparticularly, to a method and an apparatus for optimizing thetransmission/reception beams according to the signaling scenario of abase station and the operation scenario of a terminal in the 5G wirelesscommunication system.

BACKGROUND ART

To meet the demand for wireless data traffic having increased sincedeployment of 4G communication systems, efforts have been made todevelop an improved 5G or pre-5G communication system. Therefore, the 5Gor pre-5G communication system is also called a “Beyond 4G Network” or a“Post LTE System”.

The 5G communication system is considered to be implemented in higherfrequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higherdata rates. To decrease propagation loss of the radio waves and increasethe transmission distance, the beamforming, massive multiple-inputmultiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna,an analog beam forming, large scale antenna techniques are discussed in5G communication systems.

In addition, in 5G communication systems, development for system networkimprovement is under way based on advanced small cells, cloud radioaccess networks (RANs), ultra-dense networks, device-to-device (D2D)communication, wireless backhaul, moving network, cooperativecommunication, coordinated multi-points (CoMP), reception-endinterference cancellation and the like.

In the 5G system, hybrid FSK and QAM modulation (FQAM) and slidingwindow superposition coding (SWSC) as an advanced coding modulation(ACM), and filter bank multi carrier (FBMC), non-orthogonal multipleaccess (NOMA), and sparse code multiple access (SCMA) as an advancedaccess technology have also been developed.

Meanwhile, in a 5G wireless communication system, the necessity of amethod for optimizing a transmission/reception beam according tosignaling of a base station and an operation scenario of a terminal hasemerged.

DESCRIPTION OF INVENTION Technical Problem

Due to the above-mentioned necessity, this disclosure aims to optimizethe transmission/reception beam according to the signaling of a basestation and the operation scenario of a terminal in a 5G wirelesscommunication system.

Solution to Problem

A control method of a terminal in a wireless communication systemaccording to an embodiment of the disclosure may include receiving radioresource control (RRC) signaling for a signal measured by the terminal,identifying a transmission interval of the signal measured by theterminal, based on the received RRC signaling, identifying apreconfigured first beam book, and determining whether to change thefirst beam book to a second beam book, based on the identifiedtransmission interval.

A control method of a terminal in a wireless communication system,according to another embodiment of the disclosure may includeidentifying first beam book including information on a plurality ofpreconfigured beams, and changing the first beam book to the second beambook when an event in which the number of transmission/reception beamsis changed occurs.

A terminal in a wireless communication system according to anotherembodiment of the disclosure may include a transceiver configured totransmit and receive a signal, and a controller configured to controlthe transceiver to receive radio resource control signaling (RRCsignaling) for a signal measured by the terminal, identify thetransmission interval of a signal measured by the terminal, based on thereceived RRC signaling, identify a preconfigured first beam book, anddetermine whether to change the first beam book to a second beam book,based on the identified transmission interval.

A terminal in a wireless communication system according to anotherembodiment of the disclosure may include a transceiver configured totransmit and receive a signal, and a controller configured to identify afirst beam book including information on a plurality of preconfiguredbeams, and change the first beam book to a second beam book, when anevent in which the number of transmission/reception beams is changedoccurs.

Advantageous Effects of Invention

Through the disclosure, in the 5G wireless communication system, theterminal can optimize the transmit/receive beam by changing or modifyingthe beam book according to the signaling of the base station and theoperation scenario of the terminal.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram of an electronic device in a networkenvironment according to various embodiments;

FIG. 2 is a view illustrating a beamforming communication circuitaccording to various embodiments;

FIGS. 3A and 3B are views illustrating an antenna panel and hardwarestructure according to various embodiments;

FIGS. 4A and 4B are views illustrating a shape of a beam according tovarious embodiments;

FIGS. 5A to 5C are views illustrating beamforming according to variousembodiments;

FIG. 6 is a flowchart illustrating a control method of a terminalaccording to an embodiment of the disclosure;

FIGS. 7A and 7B are views illustrating a frame structure for a slot inwhich a terminal desires to perform a beam sweep according to anembodiment of the disclosure;

FIGS. 8A to 8C are views illustrating a method of selecting a portionfrom an arbitrary beam book according to an embodiment of thedisclosure;

FIG. 9 is a view illustrating a combination of beam operations between abase station and a terminal according to an embodiment of thedisclosure;

FIGS. 10A and 10B are views illustrating allocation of resources andchanges in beams of a base station and a terminal for the allocatedresources according to an embodiment of the disclosure;

FIG. 11 is a view illustrating a beam scenario of a terminal in an idlemode according to an embodiment of the disclosure,

FIG. 12 is a view illustrating a terminal existing at a cell edgeaccording to an embodiment of the disclosure; and

FIG. 13 is a block diagram illustrating the components of a terminalaccording to an embodiment of the disclosure.

MODE FOR THE INVENTION

Hereinafter, embodiments of the disclosure will be described in detailwith reference to the accompanying drawings.

In describing embodiments of the disclosure, descriptions related totechnical contents well-known in the art and not associated directlywith the disclosure will be omitted. Such an omission of unnecessarydescriptions is intended to prevent obscuring of the main idea of thedisclosure and more clearly transfer the main idea.

For the same reason, in the accompanying drawings, some elements may beexaggerated, omitted, or schematically illustrated. Further, the size ofeach element does not completely reflect the actual size. In thedrawings, identical or corresponding elements are provided withidentical reference numerals.

The advantages and features of the disclosure and ways to achieve themwill be apparent by making reference to embodiments as described belowin detail in conjunction with the accompanying drawings. However, thedisclosure is not limited to the embodiments set forth below, but may beimplemented in various different forms. The following embodiments areprovided only to completely disclose the disclosure and inform thoseskilled in the art of the scope of the disclosure, and the disclosure isdefined only by the scope of the appended claims. Throughout thespecification, the same or like reference numerals designate the same orlike elements.

Here, it will be understood that each block of the flowchartillustrations, and combinations of blocks in the flowchartillustrations, can be implemented by computer program instructions.These computer program instructions can be provided to a processor of ageneral purpose computer, special purpose computer, or otherprogrammable data processing apparatus to produce a machine, such thatthe instructions, which execute via the processor of the computer orother programmable data processing apparatus, create means forimplementing the functions specified in the flowchart block or blocks.These computer program instructions may also be stored in a computerusable or computer-readable memory that can direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer usable orcomputer-readable memory produce an article of manufacture includinginstruction means that implement the function specified in the flowchartblock or blocks. The computer program instructions may also be loadedonto a computer or other programmable data processing apparatus to causea series of operational steps to be performed on the computer or otherprogrammable apparatus to produce a computer implemented process suchthat the instructions that execute on the computer or other programmableapparatus provide steps for implementing the functions specified in theflowchart block or blocks.

Further, each block of the flowchart illustrations may represent amodule, segment, or portion of code, which includes one or moreexecutable instructions for implementing the specified logicalfunction(s). It should also be noted that in some alternativeimplementations, the functions noted in the blocks may occur out of theorder. For example, two blocks shown in succession may in fact beexecuted substantially concurrently or the blocks may sometimes beexecuted in the reverse order, depending upon the functionalityinvolved.

As used herein, the “unit” refers to a software element or a hardwareelement, such as a Field Programmable Gate Array (FPGA) or anApplication Specific Integrated Circuit (ASIC), which performs apredetermined function. However, the “unit” does not always have ameaning limited to software or hardware. The “unit” may be constructedeither to be stored in an addressable storage medium or to execute oneor more processors. Therefore, the “unit” includes, for example,software elements, object-oriented software elements, class elements ortask elements, processes, functions, properties, procedures,sub-routines, segments of a program code, drivers, firmware,micro-codes, circuits, data, database, data structures, tables, arrays,and parameters. The elements and functions provided by the “unit” may beeither combined into a smaller number of elements, or a “unit”, ordivided into a larger number of elements, or a “unit”. Moreover, theelements and “units” or may be implemented to reproduce one or more CPUswithin a device or a security multimedia card.

In the disclosure, a terminal may generally include a mobile terminal,and may refer to a device which has already subscribed to a mobilecommunication system and is provided with services from the mobilecommunication system. The mobile terminal may include a smart devicesuch as a smartphone or a tablet PC, but this device is merely anexample of the mobile terminal and the disclosure is not limitedthereto.

In the following description, terms for identifying access nodes, termsreferring to network entities, terms referring to messages, termsreferring to interfaces between network entities, terms referring tovarious identification information, and the like are illustratively usedfor the sake of convenience. Therefore, the disclosure is not limited bythe terms as used below, and other terms referring to subjects havingequivalent technical meanings may be used.

In the following description, the disclosure uses terms and namesdefined in 3rd generation partnership project long term evolution (3GPPLTE) standards for the convenience of description. However, thedisclosure is not limited by these terms and names, and may be appliedin the same way to systems that conform other standards.

The structure of the next generation mobile communication system towhich the disclosure can be applied will be briefly described. The radioaccess network of the next generation mobile communication system(hereinafter referred to as new radio (NR) or 5G) is composed of a nextgeneration base station (new radio node B, hereinafter, referred to asNR gNB or NR base station) and a new radio core network (NR CN). Theuser terminal (new radio user equipment, hereinafter referred to as NRUE or terminal) accesses an external network through NR gNB and NR CN.

The NR gNB corresponds to the evolved node B (eNB) of the existing LTEsystem. The NR gNB is connected to the NR UE through a radio channel andcan provide superior service than the existing Node B. In the nextgeneration mobile communication system, since all user traffic isserviced through a shared channel, a device is required to performscheduling by collecting status information such as the buffer state,available transmission power state, and channel state of UEs, and NR NBis in charge. One NR gNB usually controls multiple cells. In order toimplement ultra-fast data transmission compared to the current LTE, itmay have more than the existing maximum bandwidth, and an orthogonalfrequency division multiplexing (hereinafter referred to as OFDM) methodmay be additionally applied to the beamforming technology using a radioaccess technology. In addition, an adaptive modulation & coding(hereinafter referred to as AMC) scheme is applied to determine amodulation scheme and a channel coding rate according to a channel stateof a terminal. The NR CN performs functions such as mobility support,bearer configuration, and QoS configuration. NR CN is a device that isresponsible for various control functions as well as mobility managementfunctions for terminals, and is connected to multiple base stations. Inaddition, the next-generation mobile communication system can be linkedwith the existing LTE system, and the NR CN is connected to the MMEthrough a network interface. The MME is connected to the existing basestation, eNB.

The base station described below according to an embodiment of thedisclosure may refer to a 5G base station that transmits a signal usinga beam formed by beamforming in an ultra-high frequency (mmWave) band asdescribed above.

FIG. 1 is a block diagram of an electronic device 101 in a networkenvironment 100, according to various embodiments. Referring to FIG. 1,in the network environment 100, the electronic device 101 maycommunicate with an electronic device 102 via a first network 198 (e.g.,short distance wireless communication network), or may communicate withan electronic device 104 or a server 108 via a second network 199 (e.g.,long distance wireless communication network). According to anembodiment, the electronic device 101 may communicate with theelectronic device 104 via the server 108. According to an embodiment,the electronic device 101 may include a processor 120, a memory 130, aninput device 150, an audio output device 155, a display device 160, anaudio module 170, a sensor module 176, an interface 177, a haptic module179, a camera module 180, a power management module 188, a battery 189,a communication module 190, a subscriber identification module 196, oran antenna module 197. In some embodiments, at least one of thecomponents (e.g., the display device 160 or the camera module 180) maybe omitted or one or more other components may be added to theelectronic device 101. In some embodiments, some of these components maybe implemented as one integrated circuit. For example, the sensor module176 (e.g., a fingerprint sensor, an iris sensor, or an illuminancesensor) may be implemented while being embedded in the display device160 (e.g., a display).

The processor 120 may execute, for example, software (e.g., the program140) to control at least one other component (e.g., hardware or softwarecomponent) of the electronic device 101 connected to the processor 120,and may perform various data processing or operations. According to anembodiment, as at least a part of data processing or operation, theprocessor 120 may load instructions or data received from othercomponents (e.g., the sensor module 176 or the communication module 190)into a volatile memory 132, process the instructions or data stored inthe volatile memory 132, and store the result data in the nonvolatilememory 134. According to an embodiment, the processor 120 may include amain processor 121 (e.g., a central processing unit or an applicationprocessor), and an auxiliary processor 123 (e.g., a graphics processingunit, an image signal processor, a sensor hub processor, orcommunication processor) that can be operated independently or togetherwith the main processor. Additionally or alternatively, the auxiliaryprocessor 123 may be configured to use lower power than the mainprocessor 121, or to be specialized for a designated function. Theauxiliary processor 123 may be implemented separately from the mainprocessor 121 or as part of the main processor 121.

The auxiliary processor 123 may control at least some of functions orstates related to at least one component (e.g., the display device 160,the sensor module 176, or the communication module 190) among thecomponents of the electronic device 101, for example, instead of themain processor 121 while the main processor 121 is in an inactive (e.g.,sleep) state, or with the main processor 121 while the main processor121 is in an active (e.g., execute an application) state. According toan embodiment, the auxiliary processor 123 (e.g., an image signalprocessor or communication processor) may be implemented as a part ofother functionally related components (e.g., the camera module 180 orthe communication module 190).

The memory 130 may store various data used by at least one component ofthe electronic device 101 (e.g., the processor 120 or the sensor module176). The data may include, for example, software (e.g., the program140) and input data or output data for commands related thereto. Thememory 130 may include a volatile memory 132 or a nonvolatile memory134.

The program 140 may be stored as software in the memory 130, and mayinclude, for example, an operating system 142, middleware 144, or anapplication 146.

The input device 150 may receive commands or data to be used forcomponents (e.g., the processor 120) of the electronic device 101 fromoutside (e.g., a user) of the electronic device 101. The input device150 may include, for example, a microphone, a mouse, or a keyboard.

The audio output device 155 may output an audio signal to the outside ofthe electronic device 101. The audio output device 155 may include, forexample, a speaker or a receiver. The speaker may be used for generalpurposes such as multimedia playback or recording playback, and thereceiver may be used to receive an incoming call. According to oneembodiment, the receiver may be implemented separately from the speaker,or as part thereof.

The display device 160 may visually provide information to the outsideof the electronic device 101 (e.g., a user). The display device 160 mayinclude, for example, a display, a hologram device, or a projector and acontrol circuit for controlling the device. According to an embodimentof the disclosure, the display device 160 may include a touch circuitryconfigured to sense a touch, or a sensor circuit (e.g., a pressuresensor) configured to measure the strength of the force generated by thetouch.

The audio module 170 may convert sound into an electrical signal, orvice versa. According to an embodiment, the audio module 170 may acquiresound through the input device 150 or may output sound through an audiooutput device 155, and an external electronic device (e.g., theelectronic device 102) (e.g., a speaker or headphones) directly orwirelessly connected to the electronic device 101.

The sensor module 176 may detect an operating state (e.g., power ortemperature) of the electronic device 101 or an external environmentalstate (e.g., a user state), and may produce an electrical signal or datavalue corresponding to the detected state. According to an embodiment,the sensor module 176 may include, for example, a gesture sensor, a gyrosensor, a barometric pressure sensor, a magnetic sensor, an accelerationsensor, a grip sensor, a proximity sensor, a color sensor, an infrared(IR) sensor, a biological sensor, a temperature sensor, a humiditysensor, or an illuminance sensor.

The interface 177 may support one or more designated protocols that canbe used for the electronic device 101 to be directly or wirelesslyconnected to an external electronic device (e.g., the electronic device102). According to an embodiment, the interface 177 may include, forexample, a high definition multimedia interface (HDMI), a universalserial bus (USB) interface, an SD card interface, or an audio interface.

The connection terminal 178 may include a connector through which theelectronic device 101 can be physically connected to an externalelectronic device (e.g., the electronic device 102). According to anembodiment, the connection terminal 178 may include, for example, anHDMI connector, a USB connector, an SD card connector, or an audioconnector (e.g., a headphone connector).

The haptic module 179 may convert electrical signals into mechanicalstimuli (e.g., vibration or movement) or electrical stimuli that theuser can perceive through tactile or kinesthesis. According to anembodiment, the haptic module 179 may include, for example, a motor, apiezoelectric element, or an electrical stimulation device.

The camera module 180 may capture still images and videos. According toan embodiment, the camera module 180 may include one or more lenses,image sensors, image signal processors, or flashes.

The power management module 188 may manage power supplied to theelectronic device 101. According to an embodiment, the power managementmodule 388 may be implemented, for example, as at least a part of apower management integrated circuit (PMIC).

The battery 189 may supply power to at least one component of theelectronic device 101. According to an embodiment, the battery 189 mayinclude, for example, a non-rechargeable primary cell, a rechargeablesecondary cell, or a fuel cell.

The communication module 190 may support establishing a direct (e.g.,wired) communication channel or a wireless communication channel betweenthe electronic device 101 and an external electronic device (e.g., theelectronic device 102, the electronic device 104, or the server 108),and performing communication via the established communication channel.The communication module 190 may be operated independently of theprocessor 120 (e.g., an application processor), and may include one ormore communication processors supporting direct (e.g., wired)communication or wireless communication. According to an embodiment, thecommunication module 190 may include a wireless communication module 192(e.g., a cellular communication module, a short-range wirelesscommunication module, or a global navigation satellite system (GNSS)communication module) or a wired communication module 194 (e.g., a localarea network (LAN) communication module, or a power line communicationmodule). Corresponding communication module among these communicationmodules may communicate with an external electronic device through thefirst network 198 (e.g., a short-range communication network such asBluetooth, WiFi direct, or infrared data association (IrDA)) or thesecond network 199 (e.g., a long distance communication network such asa cellular network, the Internet, or a computer network (e.g., LAN orWAN)). These various types of communication modules may be integratedinto a single component (e.g., a single chip), or may be implemented asa plurality of separate components (e.g., multiple chips). The wirelesscommunication module 192 may identify and authenticate the electronicdevice 101 within a communication network such as the first network 198or the second network 199 using subscriber information (e.g.,international mobile subscriber identifier (IMSI)) stored in thesubscriber identification module 196.

The antenna module 197 may transmit a signal or power to the outside(e.g., an external electronic device) or receive it from the outside.According to an embodiment, the antenna module 197 may include one ormore antennas, and therefrom, at least one antenna suitable for acommunication method used in a communication network such as the firstnetwork 198 or the second network 199 may be selected, for example, bythe communication module 190. The signal or power may be transmitted orreceived between the communication module 190 and an external electronicdevice through the at least one selected antenna.

At least some of the components may be connected to each other via acommunication method between peripheral devices (e.g., a bus, a generalpurpose input and output (GPIO), a serial peripheral interface (SPI), ora mobile industry processor interface (MIPI)) and exchange signals(e.g., commands or data) with each other.

According to an embodiment, the command or data may be transmitted orreceived between the electronic device 101 and the external electronicdevice 104 through the server 108 connected to the second network 199.Each of the electronic devices 102 and 104 may be the same or adifferent type of device from the electronic device 101. According to anembodiment, all or some of the operations performed on the electronicdevice 101 may be performed on one or more external devices of theexternal electronic devices 102, 104, or 108. For example, when theelectronic device 101 needs to perform a certain function or serviceautomatically or in response to a request from a user or another device,the electronic device 101 may request one or more external electronicdevices to perform at least a part of the function or service instead ofor additionally to executing the function or service itself. The one ormore external electronic devices received the request may execute atleast a part of the requested function or service, or an additionalfunction or service related to the request, and deliver the result ofthe execution to the electronic device 101. The electronic device 101may process the result, as it is or additionally, and provide it as atleast part of a response to the request. To this end, cloud computing,distributed computing, or client-server computing technology may beused, for example.

FIG. 2 is a view illustrating a beamforming communication circuit havingn chains and capable of processing one data stream. The digital controlline inside the IC is omitted. The beamforming communication circuit maybe composed of a central processor (CP), intermediate frequencyintegrated circuit (IF-IC), a radio frequency integrated circuit(RF-IC), a switch, a supply modulator, a digital control line MIPI of abeamforming enveloper, I2C, PCIe, UART, USB, GPIO, etc.

As illustrated in FIG. 2, n antennas are arranged at a distance d. Atthis time, the antenna is connected to the switch and selectivelyconnects to the Tx chain when transmitting (Tx) and the Rx chain whenreceiving (Rx) during time duplex division (TDD) communication.

The transmission chain includes a power amplifier (PA), a first variablegain amplifier (1=VGA), a phase shifter (PS), a second variable gainamplifier (2^(nd) VGA), an n-way Tx splitter, and a mixer within theRF-IC.

The PA plays a role of amplifying the power of the Tx signal. The PA maybe mounted inside the RF-IC or outside the RF-IC. Each VGA is controlledby a CP and performs TX auto gain control (AGC) operation. The number ofVGAs can be increased or decreased in some cases. PS shifts the phase ofthe signal according to the beamforming angle under the control of theCP. The n Way Splitter separates and generates the Tx signal receivedfrom the Mixer into n signals. The mixer up-converts the transmissionintermediate frequency (Tx-IF) signal received from the intermediatefrequency processing integrated circuit (IF-IC) into a Tx signal (RFband). The mixer may receive a signal to mix from the internal orexternal oscillator.

The reception chain may include a low noise amplifier (LNA), a PS, a 1stVGA, an n way Rx combiner, a 2nd Rx VGA, a mixer within RF-IC.

The LNA serves as a low-noise amplification of the signal received fromthe antenna. Each VGA is controlled by the CP and performs Rx auto gaincontrol (AGC) operation. The number of VGAs may be increased ordecreased in some cases. The PS shifts the phase of the signal accordingto the beamforming angle under the control of the CP. The n Way Combinercombines signals that are phase shifted and aligned in phase. Thecombined signal is transmitted to the mixer through the 2nd VGA. Themixer down-converts the received signal from the RF band to the IF band.The mixer may receive a signal to mix from the internal or externaloscillator.

A switch that selectively connects the Rx/Tx Chain to the rear of themixer in the RF-IC is further included. If the IF frequency is high, itmay be difficult to connect the transmission line between RF-IC/IF-IC.When TDD/Rx Chain is selectively connected during TDD operation with theswitch, the number of transmission lines of RF-IC/IF-IC can be reduced.

Like the RF-IC, the IF-IC also includes a switch that selectivelyconnects the Rx/Tx chain.

The Tx chain inside the IF-IC includes a quadrature mixer, a thirdvariable gain amplifier (3^(rd) VGA), a low pass filter (LPF), a fourthvariable gain amplifier (4^(th) VGA), and a buffer. The buffer serves asa buffer when receiving a balanced Tx I/Q signal from the CP, so thatthe signal can be stably processed. The 3^(rd) VGA and 4th VGA arecontrolled by CP and act as Tx AGC. The LPF operates as a channel filterby operating the bandwidth of the baseband Tx IQ signal at a cutofffrequency. The cutoff frequency is variable. The quadrature mixerupconverts the balanced Tx I/Q signal to the Tx-IF signal.

The Rx chain inside the IF-IC includes a quadrature mixer, a 3^(rd) VGA,a low pass filter (LPF), a 4^(th) VGA, and a buffer. The buffer acts asa buffer when delivering balanced Rx I/Q through the 4^(th) VGA to theCP, so that signals can be stably processed. The 3^(rd) VGA and 4^(th)VGA are controlled by the CP and act as Rx AGC. The LPF operates as achannel filter by operating the bandwidth of the balanced Rx IQ signalin the baseband at a cutoff frequency. The cutoff frequency is variable.The quadrature mixer down-converts to an Rx-IF signal to perform abalanced Rx I/Q signal generation operation.

The Tx I/Q DAC in the CP converts the digital signal modulated by amodem into a balanced Tx I/Q signal and transmits the same to the IF-IC.The Rx I/Q ADC in the CP converts the balanced Rx I/Q signalsdown-converted by the IF-IC into digital signals and transmits the sameto the modem.

In the LTE and NR, various downlink reference signals (DL RSs) have beendesigned for a terminal to measure and estimate a channel of a basestation. Accordingly, basic signaling for beam operation may exist basedon the various DL RSs. The terminal may form a single beam book.

The beam book may include information about an antenna element, a powerlevel and a phase shift used to form an arbitrary beam, as shown inTable 1 below.

TABLE 1 Power Beam book Antenna element adjustment Phase shift Index (3× 3) Utilize 4 (0-15) level (#0-#6) (θ₀, θ₁, θ₂, θ₃, θ₄) 0000 Index (5,6, 9, 10) (#5, #3, #3, #5) (θ₀, θ₁, θ₂, θ₃) 0001 Index (5, 6, 9, 10)(#5, #3, #3, #5) (θ₀, θ₁, θ₃, θ₄) 0010 Index (5, 6, 9, 10) (#5, #3, #3,#5) (θ₀, θ₂, θ₂, θ₃) 0011 Index (5, 6, 9, 10) (#3, #4, #4, #3) (θ₁, θ₂,θ₂, θ₂) 0100 Index (5, 6, 9, 10) (#3, #4, #4, #3) (θ₂, θ₂, θ₂, θ₂) 0101Index (5, 6, 9, 10) (#3, #4, #4, #3) (θ₃, θ₂, θ₂, θ₁) 0110 Index (5, 6,9, 10) (#5, #3, #3, #5) (θ₃, θ₂, θ₂, θ₀) 0111 Index (5, 6, 9, 10) (#5,#3, #3, #5) (θ₄, θ₃, θ₁, θ₀) 1000 Index (5, 6, 9, 10) (#5, #3, #3, #5)(θ₃, θ₂, θ₁, θ₀)

The beam book shown in Table 1 shows information on a 3×3 beam formedthrough an antenna panel having a shape of 4×4.

In an NR, the terminal needs to optimize an implementation viewpoint fora Rx beam according to a base station channel. If the Rx beam isoperated in a fixed form, loss may occur in terms of performancedepending on the scenario of the terminal. Accordingly, in order toimprove this, in the disclosure, a method for optimizing the Rx beam (orRx beam book) of the terminal, based on signaling of the base stationand an operation scenario of the terminal will be described. At thistime, the optimization of the reception beam (reception beam book) maybe equally applied from the viewpoint of the transmission beam(transmission beam book).

First, FIGS. 3A and 3B are views illustrating antenna panels 310 and 320and hardware structure of a terminal 300, according to variousembodiments. As illustrated in FIGS. 3A and 3B, the terminal 300 mayinclude a plurality of antenna panels 310 and 320. Each of the antennalpanels 310 and 320 may include antennal element. At this time, theantenna element may be 9, 16, or 25, and the number of antenna elementsincluded in one antenna panel is not limited. Also, the number of theantenna elements included in each of the first antenna panel 310 and thesecond antenna panel 320 may be different. In addition, the antenna mayinclude at least a patch type antenna or a dipole type antenna.

For example, as illustrated in FIG. 3A, the first antenna panel 310 mayinclude 16 antenna elements, and the second antenna panel 320 mayinclude four antenna elements. In addition, as illustrated in FIG. 3B,the first antenna panel 310 and the second antenna panel 320 may eachinclude four antenna elements.

When the number of antenna elements is 16 in an arbitrary antenna panel,power adjustment in each antenna element is possible in 7 operations,and when the phase shift can be adjusted in 5 operations, a plurality ofbeams may be formed. The plurality of beams may be used for calibrationpurposes. In other words, the plurality of beams may be used in hardwareto test whether the arbitrary antenna panel works well. In addition, anRx beam book may be configured by using some arbitrary number of beamsfrom a plurality of beams.

Hereinafter, a description referred to as a beam book change may be madeto change the beam book set, or may be implemented in a form of changingor modifying the configuration of the beam book itself. In other words,the change of the beam book set can also be interpreted as a change ormodification of the beam book in a broad sense.

According to various embodiments, the design of the beam book ispossible in the form of 3×3, 5×5, and 7×7. For example, assuming a patchantenna, a wide beam may constitute a beam by dividing the entire 180degree angle into three. The angle between the central axes of each beammay be 45, 60, 75, and the like. The medium beam may constitute a beamby dividing the total 180-degree angle into five. The angle between thecentral axes of each beam may be 22.5 or 30 degrees. The narrow beam mayform a beam by dividing the total 180-degree angle into seven. The anglebetween the central axes of each beam may be 15, 20, 22.5 degrees, andthe like. Various designs of the beam book are as shown in FIG. 4A. Inaddition, the width of each beam in each design may be different asshown in FIG. 4B.

Meanwhile, the first antenna panel 310 and the second antenna panel 320may use the same reception beam book, or different beam books. Forexample, even if the first antenna panel 310 sets the reception beambook in the form of 3×3, the second antenna panel 320 may also configurea reception beam in 5×5 and 7×7 forms as well as 3×3 forms. In otherwords, when the first antenna panel 310 is configured as a beam book A,the second antenna panel 320 may be configured as A or B.

In another embodiment, in the case that the reception beam book isconfigured in a 3×3 form in the first antenna panel 310, when thereception beam book of the first antenna panel 310 is changed ormodified, the reception beam book of the second antenna panel 320 may beaccordingly changed in the same manner. In this case, the first antennapanel 310 and the second antenna panel 320 may be synchronized.Therefore, when the reception beam book of the first antenna panel 310is changed from A to A′, the reception beam book of the second antennapanel 310 may also be changed from A to A′. Alternatively, the receptionbeam book of the second antenna panel 320 may be changed from B to B′.

In another embodiment, when a reception beam book is formed in the formof 3×3 in the first antenna panel 310, and then the reception beam bookof the first antenna panel 310 is changed or modified, accordingly, thereception beam book of the second antenna panel 320 may be changed to adifferent beam book. In other words, when the beam book of the firstantenna panel 310 is changed from A to A′, the beam book of the secondantenna panel 320 may also be changed from A′ to A. Alternatively, thereception beam book of the second antenna panel 320 may be changed fromB′ to B.

Various embodiments described above may be extended or changed.

Meanwhile, FIGS. 5A to 5C are views illustrating beamforming accordingto various embodiments.

FIG. 5A is a view illustrating an antenna panel 500 having four antennaelements that operate a total of 9 beams in 3D by operating a wide beam,according to an embodiment. Even the antenna panel operating the widebeam may operate three beams in a fan shape. In addition, the number ofantenna elements included in the antenna panel 500 capable of operatingthe wide beam is not limited. In other words, an antenna panel including16 antenna elements can operate a wide beam to operate a total of 9beams in 3D.

FIG. 5B is a view illustrating an antenna panel 510 having 16 antennaelements that operate a total of 25 beams in 3D by operating a mediumbeam, according to another embodiment. Even the antenna panel 510operating the medium beam may operate five beams in a fan shape. Inaddition, the number of antenna elements included in the antenna panel510 capable of operating the medium beam is not limited. In other words,an antenna panel including four antenna elements can also operate amedium beam to operate a total of 25 beams in 3D.

Meanwhile, FIG. 5C is a view explaining an antenna panel that operates atotal of 49 beams in 3D by operating a narrow beam. Even the antennapanel that operates the narrow beam may operate seven beams in a fanshape. The number of antenna elements included in the antenna paneloperating the narrow beam is not limited.

Table 2 below is a table showing a hierarchy mapping method of the beambook based on the contents shown in FIGS. 5A to 5C.

TABLE 2 Beam level (per Beam change Beam plane; Sharpening WideningChanging unchanged Wide I→A, B, F or G — I→II, IV or V Unchanged, beamII→B, C, D, G, H or I II→I, III or IV Beam fixed (three) III→D, E, I orH or V or VI (Duplicates can be III→II, V or VI excluded) Medium A→8, 9,or 2 A, B, F, G→I A→B, F or G Unchanged, beam . . . B, C, D, G, H, I→IIB→A, F, G, H or C Beam fixed (five) K→17, 18, 19, 24, 25, D, E, I, H→III. . . (Around the 26, 31, 32 or 33 beam 1tier) or . . . (Around theX→41, 42 or 49 beam 2tier) Narrow — 8, 9, or 2→A Around the Unchanged,beam . . . beam 1tier or Beam fixed (seven) 17, 18, 19, 24, 25, 26,Around the 31, 32 or 33→K beam 2tier . . . 41, 42 or 49→X

First, changing the beam from the wide beam as shown in FIG. 5A to themedium beam as shown in FIG. 5B may correspond to sharpening in whichthe width of the beam is narrowed. As an example of sharpening, the beamcorresponding to the position I of FIG. 5A may be narrowed to a beamcorresponding to the position A, position B, position F or position G ofFIG. 5B. In addition, as an example of changing, the beam correspondingto the position I of FIG. 5A may be changed to a beam corresponding tothe position II, the position IV, or the position V.

In addition, changing the beam from a medium beam as shown in FIG. 5B toa narrow beam as shown in FIG. 5C may also correspond to sharpening inwhich the width of the beam is narrowed. As an example of sharpening,the width corresponding to the position A of FIG. 5B may be narrowed tothe beam corresponding to the position 8, position 9, or position 2 ofFIG. 5C.

Meanwhile, changing a beam from a medium beam as shown in FIG. 5B to awide beam as shown in FIG. 5A may correspond to widening in which thewidth of the beam is widened. As an example of widening, the beamcorresponding to the position A, the position B, the position F, or theposition G in FIG. 5B may be widened to a beam corresponding to theposition I in FIG. 5A.

Meanwhile, as an example of changing, the beam corresponding to theposition A of FIG. 5B may be changed to a beam corresponding to theposition B, the position F, or the position G.

Changing the beam from the narrow beam as shown in FIG. 5C to the mediumbeam as shown in FIG. 5B may correspond to widening in which the widthof the beam is widened. As an example of widening, the beamcorresponding to the position 8, position 9, or position 2 in FIG. 5Cmay be widened to the beam corresponding to the position A in FIG. 5B.

Although omitted in Table 2, if a narrower beam width can beimplemented, the narrow beam shown in FIG. 5C may also be sharpened.

Hereinafter, a control method of a terminal according to an embodimentof the disclosure will be described based on FIG. 6.

First, in operation S600, the terminal may configure a default beambook. For example, when the terminal is shipped, a default beam book maybe configured and shipped.

In operation S610, the terminal may perform a radio resource control(RRC) connection with the base station. For example, the terminal maytransmit an RRC connection request message to the base station.Accordingly, when the base station transmits an RRC connection setupmessage to the terminal, the terminal transmits an RRC connection setupcomplete message to the base station, so that the terminal and the basestation can perform an RRC connection.

Although the terminal has been described as configuring the default beambook and performing RRC connection, this is only an example, and theterminal may determine the default beam book at the time of RRCconnection.

Then, in operation S620, the terminal may determine whether apredetermined event has occurred. When a predetermined event occurs, theprocess proceeds to operation S630, where the terminal can change thebeam book. The beam book may include both a reception beam book and atransmission beam book. In other words, the terminal may change thereception beam book when a preconfigured event for changing thereception beam book occurs, or may change the transmission beam bookwhen a preconfigured event for changing the transmission beam bookoccurs.

Hereinafter, a case in which a preconfigured event occurs, based onvarious embodiments of the disclosure will be described in detail.

First, the terminal may change the beam book according to a resourceallocated to the terminal or a frame structure.

Assuming that one received beam measurement is performed during onesymbol while the transmission beam is fixed, 49 symbols are needed tomeasure by sweeping 49 beams. For example, when measuring beams from 14symbols included in one slot, four slots are needed to sweep all thebeams at least once. However, the measurement by sweeping 49 beams isonly an example, and the number of beams that are measured by sweepingis not limited to 25, 16, or 9 beams.

At this time, the terminal may change or modify the reception beam bookto reduce the time to sweep. Specifically, the terminal may operate thereception beam during X slots.

Case A) As illustrated in FIG. 7A, if it is desired to measure thereception beam of the terminal with respect to the transmission beamfixed in the three slots, the number of the reception beams of theterminal can be reduced to within 14×3 symbols.

Case B1) If the CSI-RS, the synchronization signal block (SSB), and theCORESET are designed to the same symbol, While trying to measure thereception beam of the terminal with respect to the transmission beamfixed in the two slots as shown in FIG. 7B, the number of the receptionbeams of the terminal can be reduced to 14×2 or less.

Case B2) If the CSI-RS and the CORESET are not configured to the samesymbol, except for the CORESET symbol 2 (pieces), while attempting tomeasure the reception beam of the terminal with respect to thetransmission beam fixed in the two slots, the number of reception beamsof the terminal can be reduced to within 12×2.

Case B3) If SSB and CORESET are not designed to the same symbol, exceptfor SSB symbol 4 (pieces), while attempting to measure the receptionbeam of the terminal with respect to the transmission beam fixed in thetwo slots, the number of the reception beams of the terminal can bereduced to within 10×2. In other words, the terminal should be able tooperate within 20 (e.g., 16 or 9) reception beam books.

Case C1) If CSI-RS, SSB and CORESET are designed in the same symbol,while measuring the received beam of the terminal with respect to thetransmission beam fixed in one slot, the number of the reception beamsof the terminal can be reduced to 14 or less.

Case C2) If CSI-RS and CORESET are not designed to the same symbol,except for SSB symbol 2 (pieces), while attempting to measure thereception beam of the terminal with respect to the transmission beamfixed in the one slot, the beam can be measured in 12 symbols. In thiscase, 12 reception beam books should be able to operate.

Case C3) If SSB and CORESET are not designed on the same symbol, whileattempting to measure the reception beam of the terminal with respect tothe transmission beam fixed in the one slot, beams can be measured on 10symbols except for SSB symbol 4 (pieces). In this case, it should bepossible to operate up to 10 (e.g., 9) reception beam books.

According to the above-described embodiment, in order to change thereception beam book to a beam book that includes information on asmaller number of beams, the terminal may first determine the defaultreceived beam book at the time of RRC connection. For example, a set oftransmission beam books of the base station may be determined based onthe SSB configuration of the base station, reference signal (RS)configuration, or quasi-co-location (QCL) configuration. Furthermore,the terminal can determine the default received beam book. As describedabove, the default reception beam book may be configured at the time ofshipment of the terminal. As described above, the default beam book maybe a beam book including information on 3, 5, 7, 9, 25 or 49 beamsdepending on the beam shape (or beam width).

Meanwhile, the terminal may additionally configure a beam book. Forexample, the terminal may configure an additional beam book inassociation with a default beam book or independently of the defaultbeam book. Specifically, the terminal may configure a beam book forperforming measurement on 20 symbols as an additional beam book inpreparation for a case where one CORESET may be configured, whileconfiguring a beam book including information on 25 beams as a defaultbeam book.

For example, the terminal may configure a beam book includinginformation on 9 beams in a 3×3 format or a beam book includinginformation on 16 beams in a 4×4 format as the additional beam book.

As another example, the terminal may configure the additional beam bookby selecting information on some beams from a beam book that includesinformation on 25 beams. For example, as illustrated in FIG. 8A, theterminal may configure an additional beam book including information onalternately positioned beams so that the beams can be included in aneven distribution. An additional beam book including information on thebeam shown in FIG. 8A may include information on 13 beams.

Alternatively, an additional beam book including information on the beamas shown in FIG. 8B or 8C may be configured to exclude information onthe beam that is determined to be relatively insignificant or to includeinformation on the beam that is determined to be more important. Theadditional beam book including information on the beam illustrated inFIG. 8B may include information on 17 beams. In addition, the additionalbeam book including information on the beam illustrated in FIG. 8C mayinclude information on 15 beams.

Alternatively, a set for a case where a terminal wants to quickly scan areceived beam book in a slot may be included. In this case, a beam bookincluding information on up to 14 beams may be selected. In addition, abeam book including information on up to 12 or 10 beams may be selectedaccording to the number of symbols of CORESET or SSB. This beam book of3×3 format can be configured, and 14 beams out of 25 can be extracted.In this case, 14 beams may be selected by alternately selectinginformation about the beam.

Meanwhile, the width of the beam in the above-described content may becomposed of 2 or 3. For example, the beam can be a narrow beam, a mediumbeam, a wide beam, or the like.

In addition, the beam book may be further updated after operation S610of FIG. 6. At this time, a part of the beam book of the terminal may bechanged adaptively. For example, some beams corresponding to O, P, R, J,K, L, G, H, and I of FIG. 8A may be updated in the form of FIG. 8B.Alternatively, instead of the V Rx beam of 3×3 in FIG. 5A, it may beconfigured by changing to a beam corresponding to O, P, R, J, K, L, G,H, I in FIG. 5B (partial beam book change update).

At this time, the beam book design may include all combinationsconsidered in FIGS. 4A and 4B. In addition, the above-described contentsmay be additionally applied in the proposal contents described later.

According to another embodiment of the disclosure, the terminal maychange or modify the reception beam book according to the initial accessoperation and the RRC configuration.

First, in the initial access section, by using the beam configuration P1(BM configuration P1), the terminal can utilize the default beam bookset as the default. In addition, a beam pair link between the basestation and the terminal may be determined based on the basic beam book.The reception beam book (Rx beam book) used to determine the determinedtransmission beam (Tx beam) of the base station and the reception beam(Rx beam) of the terminal may be continuously used while monitoring thePDCCH.

Meanwhile, reference signal (RS) configuration by RRC configuration orRS reconfiguration by RRC reconfiguration may be performed.

In the RRC configuration, the beam book of the terminal may be operatedand changed/modified according to the configuration of QCL type D(spatial QCL) and the configuration of transmission configurationinformation (TCI).

Alternatively, the K beam for the PDCCH may be configured in the TCIstates obtained in the RRC configuration, wherein the terminal mayupdate the reception beam book in consideration of the K. For example,in order for the base station to operate the beam in the RRCconfiguration, the base station may transmit a TCI state includinginformation on the identifier to which the beam is mapped, so that theterminal can receive the PDDCH.

At this time, the terminal may select a number of reception beam bookslarger than K in consideration of the K. For example, when the K valueis 8, the number of beams included in the reception beam book may beselected as a value greater than 8 (e.g., 3×3). When the K value is 16,a value in which the number of beams included in the reception beam bookis 16 or more (e.g., 4×4, 5×5 or 7×7) may be selected.

In the above example, an example in which the number of received beambooks is configured to be larger than the set transmission beam value isgiven, but is not limited to the above value. For example, the terminalmay update the beam book according to the K value. If K is 4, the beambook is configured as A, and if K is 8, it can be changed to B.

Alternatively, a 2^(N) beam for PDSCH may be configured in TCI statesobtained in RRC configuration. At this time, the terminal may update thereception beam book in consideration of the 2^(N). The update of thereception beam book considering the 2^(N) may select a number ofreception beam books greater than 2^(N). For example, when the 2^(N)value is 16, the number of beams constituting the reception beam bookmay be selected as a value greater than 16 (e.g., 5×5 or 7×7).Alternatively, when the 2^(N) value is 25, a value in which the numberof beams constituting the reception beam book is 25 or more (e.g., 7×7)may be selected.

In the above example, an example in which the number of reception beambooks is configured to be greater than the configuration value of thetransmission beam is given, but the disclosure is not limited thereto.For example, a reception beam book including information on a number ofbeams equal to or less than the configured number of transmission beamsmay be selected.

Meanwhile, the terminal may configure the reception beam book for thebeam for the PDCCH and the beam for the PDSCH, respectively, but maypreferentially determine the beam book for the PDCCH over the beam bookfor the PDSCH. For example, if a reception beam book for receiving aPDCCH is configured, a PDSCH can be received using the configuredreception beam book.

Conversely, a beam book for PDSCH may be preferentially determined overa beam book for PDCCH. In this case, when a reception beam book forreceiving a PDSCH is configured, a PDCCH can be received using theconfigured reception beam book.

Meanwhile, BM configuration P2 is a configuration for a scenario inwhich the width of a beam is changed or deformed, such as when a widebeam/medium beam is changed to a medium beam/narrow beam. For example,the base station may perform beam sweep for the purpose of changing thenarrow beam for throughput enhancement of the terminal. In other words,during the periodic CSI-RS measuring, the terminal may perform twooperations.

First, a method of using the same reception beam book previously usedwill be described.

As shown in FIG. 9, a base station can sweep the transmission beam to 0,1, 2. The periodic CSI-RS/semi-persistent (SP) CSI-RS may change thetransmission beam in the form of 0, 1, 2, . . . using at least onesymbol within at least one slot. At this time, the terminal may utilizea basic beam book having a wide or medium beam width such as 3×3 or 5×5.

As another embodiment, as shown in FIG. 7 below, the base station maysweep the transmission beam into narrow beams within 0 beams.Specifically, the periodic/SP CSI-RS may change the transmission beam toin the form of 0, 0a, 0b, 0c using at least one symbol in at least oneslot. At this time, 0 beam may or may not be included. At this time, theterminal may utilize a basic beam book having a wide or medium beamwidth such as 3×3 or 5×5.

According to another embodiment, the terminal may change or modify thebeam book to a reception beam book composed of narrow beams.

As shown in FIG. 9, the base station may sequentially configure or fixthe transmission beams in order of 0, 1, and 2. The periodic/SP CSI-RSmay sequentially configure or fix the transmission beam to 0 and thebeam in sequence using consecutive symbols within at least one slot. Theterminal can sweep the beam in the form of X (can be removed), X1, X2,X3. X may utilize a basic beam book having a wide or medium beam width,and X1, X2, and X3 may be changed/transformed into a beam book having amedium or narrow beam width.

The terminal may repeatedly determine a transmission beam of the basestation, based on a parameter transmitted by the base station, andoperate based on the determination result. For example, the terminal mayutilize the CSI-RS-ResourceRep parameter. Specifically, when theCSI-RS-ResourceRep of the RRC parameter in the higher layer isconfigured as ‘ON’ or ‘OFF’ in MAC CE or downlink control information(DCI), the terminal may operate to change/modify the beam book, based onthe above configuration.

According to another embodiment, in FIG. 9, the base station maysequentially configure or fix the transmission beams as 0a, 0b, and 0c.The periodic/SP CSI-RS may configure or fix the transmission beam to 0ausing consecutive symbols in at least one slot. The terminal may sweepthe beam in the form of X (can be removed), X1, X2, X3. X may utilize abasic beam book having a wide or medium beam width, and X1, X2, and X3may be changed/modified into a beam book having a medium or narrow beamwidth.

The terminal may repeatedly determine a transmission beam of the basestation, based on a parameter transmitted by the base station, andoperate based on the determination result. For example, the terminal mayutilize the CSI-RS-ResourceRep parameter. Specifically, if theCSI-RS-ResourceRep of the RRC parameter in the higher layer isconfigured as ‘ON’ or ‘OFF’ in MAC CE or DCI, the terminal may operateto change/modify the beam book, based on the above configuration.

Meanwhile, according to another embodiment of the disclosure, in theabove description, the terminal may be configured by changing/modifyingthe reception beam book to a beam book constituting the same narrow orwide beam depending on the situation. At this time, the terminal may usethe same beam book as the configured beam book when determining thereception beam book for the PDCCH.

Hereinafter, a method for changing/modifying a reception beam book of aterminal according to DCI signaling will be described based on FIGS. 10Aand 10B. FIGS. 10A and 10B are views illustrating a change and a framestructure of a reception beam of a terminal and allocated resources.

As described in FIGS. 10A and 10B, a transmission beam corresponding toPDCCH and PDSCH transmitted by a base station may be different. Forexample, when the width of the beam transmitted by the base station isnarrower in the PDSCH transmission interval than in the transmissioninterval of the control resource set (CORESET), as shown in FIG. 10A,the terminal may maintain the reception beam book as it is. On the otherhand, as shown in FIG. 10B, the terminal may change the reception beambook corresponding to the PDSCH transmission period from the first beambook to the second beam book.

As described above in FIG. 9, in the BM configuration P2/P3, when thetransmission beams are 0a, 0b, 0c, 1a, 1b, 1c, 2a, 2b, 2c at 0, 1, 2 inbeam switch transmission, and the reception beams are X1, X2, and X3,they may correspond.

If the RRC parameter in the higher layer is “Is-TCI-Present=True” byperforming PDCCH decoding in the CORESET, the terminal may change thebeam according to the TCI field value in DCI (e.g., 3 bits). Forexample, when the transmission beam is changed from 0 to 0a as shown inFIG. 10B, the terminal may maintain the beam as a wide beam or a mediumbeam, such as beam X, for PDCCH reception. Alternatively, the terminalmay change the reception beam book to a medium beam or a narrow beam asin beam X1 for PDSCH reception.

In addition, if the RRC parameter is “Is-TCI-Present=False” in thehigher layer by performing PDCCH decoding in the CORESET, thetransmission beam of the base station may fall back according to thiscondition. For example, the transmission beam may be changed from 0a to0. At this time, the terminal may maintain the beam in the medium beamor narrow beam as in beam X1 for PDSCH reception. Alternatively, theterminal may fall back the reception beam book in a wide beam or amedium beam, such as beam X, for PDSCH reception.

According to an embodiment, the terminal may manage the reception beambook for receiving the PDSCH and the reception beam book for receivingthe PDCCH in the same manner or may separately manage them. For example,if a separate falling back does not exist when the beam book is changedbased on a specific time point, the terminal may use the continuouslymodified beam book for reception of the PDCCH or PDSCH. However, if theterminal separately manages the reception beam book for the reception ofthe PDSCH and the PDCCH, falling back may affect only the PDSCHoperation.

According to another embodiment of the disclosure, the terminal maychange the reception beam book when performing beam failure detection orbeam failure declaration. For example, if reception of all PDCCHs amongat least one PDCCH transmitted by the base station fails, the terminalmay perform beam failure detection or beam failure declaration. Inaddition, when performing a beam failure confirmation or declaration,the terminal may change to the second beam book including information ona greater number of beams than the first beam book.

Specifically, if the terminal fails to receive all PDCCHs among at leastone PDCCH received from the serving base station, and the receptionfailure of the PDCCH continues for a predetermined time or more, theterminal may perform beam failure confirmation or declaration. At thistime, the terminal should additionally sweep a candidate Tx beam of anew base station. Accordingly, the terminal may change the beam bookused by the terminal based on the beam failure declaration. For example,a terminal that has previously used a medium beam book can change thereception beam book to a wide beam book for fast beam failure recoveryafter a beam failure declaration. As a result, the terminal can quicklyperform the reception beam sweep in a predetermined time window.

According to another embodiment of the disclosure, the terminal maychange the reception beam book in the RRC idle mode or in the wake upphase in the idle mode. An example in which the terminal is receiving asignal in the first beam book and entering an idle mode in the connectedmode will be described. At this time, in order to receive a pagingsignal in the idle mode, the terminal may change to the second beam bookincluding information on fewer beams than the first beam book.

Specifically, in SSB information transmitted from the base station,location-related information of a common CORESET may be included andtransmitted. The terminal may identify the beam-related information ofCommon CORESET, based on the received information. The beam-relatedinformation may include the location of the Common CORESET and the indexof the corresponding beam. As shown in FIG. 11, paging information maybe configured in the form of continuous paging time slots such as alt 1(1100), or non-continuous paging time slots such as alt 2 (1110). Theterminal receiving the SSB information may change or modify thereception beam book, based on the received information. For example,when using a beam book having a wide beam width, the possibility ofreceiving a CORESET necessary to receive information on paging of aterminal may increase. If the beam or beam book used in the connectionmode was operated using a medium beam or a narrow beam (e.g., X1, X2, orX3 in FIG. 9 described above), when entering the idle mode, the terminalmay change the beam book to a beam book composed of a wide beam (e.g., Xin FIG. 9 described above).

If the beam sweeping in all directions for paging of the base station isrepeated at least two times as shown in FIG. 11, the terminal may changethe reception beam or the reception beam book, based on thisinformation. For example, when the first beam sweep is the receptionbeam X of the terminal, the second beam sweep may be operated as X+1(change of Rx beam) or X1 (change of RX beam book). When the number oftimes the beam sweeping is performed is plural, it is possible tooperate the reception beam using such a hierarchy.

In addition, if the resource to which the SSB is allocated is the sameas the paging time slot as shown in FIG. 11 (FDMed on resources), theterminal may use the same reception beam book in the common CORESETsection for paging through SSB monitoring. At this time, the terminalmay reuse the beam book configured for initial use.

According to another embodiment of the disclosure, the beam book may bechanged according to the location of the terminal 1200. Specifically, asillustrated in FIG. 12, when the terminal 1200 is located at the celledge of the cell 1210, the terminal 1200 may determine that powerenhancement is required. Accordingly, the terminal 1200 may change thereception beam book to include information about the narrow-shaped beam.

In determining that the terminal 1200 is located at the edge of the cell1210, it may be determined using a received signal strength indicator(RSSI), a reference signal received power (RSRP), and a reference signalreceived quality (RSRQ) value by utilizing an omni beam. Alternatively,the terminal 1200 may determine whether it is present at the cell edge,based on at least one of the received global positioning system (GPS)signal and the signal strength received from other base stations locatedin the vicinity.

In a scenario in which the terminal requires power enhancement, when thereception beam book of the terminal is changed to form a narrow beamwidth, the terminal 1200 may preferentially change the PDSCH. Inaddition, the terminal 1200 may additionally change the PDCCH.

Modification of the reception beam book of the terminal describedaccording to an embodiment of the disclosure may be designed in ahierarchical form of one reception beam book. In addition, thehierarchical single reception beam book form may be applied to theabove-described embodiments.

In the above-described method, the reception beam or the reception beambook of the terminal is operated according to the transmission beaminformation, signaling, and scenario situation of the base station tominimize the reception sensitivity and beam sweep operation of theterminal and to reduce the power consumption of the terminal.

FIG. 13 is a block diagram illustrating the components of a terminalaccording to an embodiment of the disclosure.

The terminal 1300 may include a transceiver 1310 and a controller 1320.

The transceiver 1310 is a component for transmitting and receivingsignals. The terminal 1300 may transmit/receive a signal to/from a basestation or another terminal through the transceiver 1310.

The controller 1320 may control the terminal 1300 as a whole.Specifically, the controller 1320 controls the transceiver 1310 toreceive radio resource control signaling (RRC signaling) for a signal tobe measured by the terminal 1300, identify the number of slots throughwhich the signal to be measured by the terminal is transmitted, based onthe received RRC signaling, identify a preconfigured first beam book,and compare the predetermined number of slots through which the firstbeam book and the signal to be measured are transmitted to determinewhether to change the first beam book to a second beam book.

Meanwhile, when the number of beams transmitted according to the firstbeam book is less than the number of the identified slots, thecontroller 1320 may determine to change to the second beam book thatincludes information on a smaller number of beams than the first beambook.

At this time, the signal to be measured of the terminal 1300 may becharacterized in that it includes at least one of CSI-RS and SSB.

In addition, the second beam book may be formed by selecting informationon an arbitrary number of beams from information on a plurality of beamsincluded in the first beam book.

Meanwhile, the controller 1320 may identify a beam configured to receivea physical downlink control channel (PDCCH) and a physical downlinkshared channel (PDSCH), based on the received RRC signaling, and maydetermine whether to change the first beam book to the second beam book,based on the beam configured for the PDCCH and the PDSCH.

According to another embodiment of the disclosure, the controller 1320may identify a first beam book including information on the configuredplurality of beams, and may change the first beam book to a second beambook when an event in which the number of transmit and reception beamsis changed occurs.

In addition, when the width of the beam transmitted from the basestation is narrower in the PDSCH transmission period than in the controlresource set (CORESET), the controller 1320 may change the receptionbeam book of the terminal 1300 corresponding to the PDSCH transmissionperiod from the first beam book to the second beam book.

In addition, when reception of all PDCCHs among at least one PDCCHtransmitted by the base station has failed, the controller 1320 mayperform a beam failure declaration, and when performing the beam failuredeclaration, may change to the second beam book including information ona greater number of beams than the first beam book.

In addition, when the terminal 1300 enters an idle mode from a connectedmode, in order to receive a paging signal in the idle mode, thecontroller 1320 may change to the second beam book including informationon fewer beams than the first beam book.

Specifically, based on at least one of a received signal strengthindicator (RSSI), a reference signal received power (RSRP) value, areference signal received quality (RSRQ) value, a received globalpositioning system (GPS) signal, and a signal strength received fromanother base station, the controller 1320 may identify whether theterminal 1300 exists at a cell edge, and may change to the second beambook including information on a greater number of beams than the firstbeam book When the terminal 1300 is present at the cell edge.

The electronic device according to various embodiments may be one ofvarious types of electronic devices. The electronic devices may include,for example, a portable communication device (e.g., a smart phone), acomputer device, a portable multimedia device, a portable medicaldevice, a camera, a wearable device, or a home appliance. The electronicdevice according to embodiments of the disclosure is not limited tothose described above.

It should be appreciated that various embodiments of the disclosure andthe terms used therein are not intended to limit the technologicalfeatures set forth herein to particular embodiments and include variouschanges, equivalents, or alternatives for a corresponding embodiment.With regard to the description of the drawings, similar referencenumerals may be used to designate similar or relevant elements. It is tobe understood that a singular form of a noun corresponding to an itemmay include one or more of the things, unless the relevant contextclearly indicates otherwise. As used herein, each of such phrases as “Aor B,” “at least one of A and B,” “at least one of A or B,” “A, B, orC,” “at least one of A, B, and C,” and “at least one of A, B, or C,” mayinclude all possible combinations of the items enumerated together in acorresponding one of the phrases. As used herein, such terms as “afirst”, “a second”, “the first”, and “the second” may be used to simplydistinguish a corresponding element from another, and does not limit theelements in other aspect (e.g., importance or order). It is to beunderstood that if an element (e.g., a first element) is referred to,with or without the term “operatively” or “communicatively”, as “coupledwith,” “coupled to,” “connected with,” or “connected to” another element(e.g., a second element), it means that the element may be coupled withthe other element directly (e.g., wiredly), wirelessly, or via anotherelement (e.g., third element).

As used herein, the term “module” may include a unit implemented inhardware, software, or firmware, and may be interchangeably used withother terms, for example, “logic,” “logic block,” “component,” or“circuit”. The “module” may be a minimum unit of a single integratedcomponent adapted to perform one or more functions, or a part thereof.For example, according to an embodiment, the “module” may be implementedin the form of an application-specific integrated circuit (ASIC).

Various embodiments as set forth herein may be implemented as software(e.g., the program 140) including one or more instructions that arestored in a storage medium (e.g., internal memory 136 or external memory138) that is readable by a machine (e.g., the electronic device 101).For example, a processor (e.g., the processor 120) of the machine (e.g.,the electronic device 101) may invoke at least one of the one or moreinstructions stored in the storage medium, and execute it, with orwithout using one or more other components under the control of theprocessor. This allows the machine to be operated to perform at leastone function according to the at least one instruction invoked. The oneor more instructions may include a code generated by a complier or acode executable by an interpreter. The machine-readable storage mediummay be provided in the form of a non-transitory storage medium. Wherein,the term “non-transitory” simply means that the storage medium is atangible device, and does not include a signal (e.g., an electromagneticwave), but this term does not differentiate between where data issemi-permanently stored in the storage medium and where the data istemporarily stored in the storage medium.

According to an embodiment, a method according to various embodiments ofthe disclosure may be included and provided in a computer programproduct. The computer program product may be traded as a product betweena seller and a buyer. The computer program product may be distributed inthe form of a machine-readable storage medium (e.g., compact disc readonly memory (CD-ROM)), or be distributed (e.g., downloaded or uploaded)online via an application store (e.g., Play Store™), or between two userdevices (e.g., smart phones) directly. If distributed online, at leastpart of the computer program product may be temporarily generated or atleast temporarily stored in the machine-readable storage medium, such asmemory of the manufacturer's server, a server of the application store,or a relay server.

According to various embodiments, each element (e.g., a module or aprogram) of the above-described elements may include a single entity ormultiple entities. According to various embodiments, one or more of theabove-described elements may be omitted, or one or more other elementsmay be added. Alternatively or additionally, a plurality of elements(e.g., modules or programs) may be integrated into a single element. Insuch a case, according to various embodiments, the integrated elementmay still perform one or more functions of each of the plurality ofelements in the same or similar manner as they are performed by acorresponding one of the plurality of elements before the integration.According to various embodiments, operations performed by the module,the program, or another element may be carried out sequentially, inparallel, repeatedly, or heuristically, or one or more of the operationsmay be executed in a different order or omitted, or one or more otheroperations may be added.

The invention claimed is:
 1. A control method of a terminal in awireless communication system, the method comprising: receiving radioresource control (RRC) signaling for a signal measured by the terminal;identifying a transmission interval of the signal measured by theterminal, based on the received RRC signaling; identifying firstinformation for forming a preconfigured beam; and determining whether tochange the first information for forming the beam to second informationfor forming a beam, based on the identified transmission interval,wherein the identifying the transmission interval of the signal measuredby the terminal comprises identifying the number of slots or symbols towhich the signal measured by the terminal is transmitted, wherein thedetermining comprises determining by comparing the number of beams ofthe first information for forming the beam and the number of slots orsymbols to which the signal measured by the terminal is transmitted,wherein the signal measured by the terminal comprises at least one ofchannel state information-reference signal (CSI-RS) and synchronizationsignal/broadcast block (SSB), wherein the second information for formingthe beam is formed by selecting information on an arbitrary number ofbeams from information on a plurality of beams included in the firstinformation for forming the beam, wherein the determining comprises:determining to change to the second information for forming the beamincluding information on a smaller number of beams than the firstinformation for forming the beam in case that the number of beamstransmitted according to the first information for forming the beam isless than the number of the identified slots.
 2. The method of claim 1,further comprising: identifying a beam configured to receive a physicaldownlink control channel (PDCCH) and a physical downlink shared channel(PDSCH), based on the received RRC signaling, wherein the determiningcomprises determining whether to change the first information forforming the beam to the second information for forming the beam, basedon the beam configured for the PDCCH and the PDSCH.
 3. A terminal in awireless communication system, the terminal comprising: a transceiverconfigured to transmit and receive a signal; and a controller configuredto control the transceiver to receive radio resource control signaling(RRC signaling) for a signal measured by the terminal, identify atransmission interval of a signal measured by the terminal, based on thereceived RRC signaling, identify first information for forming apreconfigured beam, and determine whether to change the firstinformation for forming the beam to second information for forming abeam, based on the identified transmission interval, wherein the signalmeasured by the terminal comprises at least one of channel stateinformation-reference signal (CSI-RS) and synchronizationsignal/broadcast block (SSB), and wherein the second information forforming the beam is formed by selecting information on an arbitrarynumber of beams from information on a plurality of beams included in thefirst information for forming the beam, wherein the controlleridentifies the number of slots and symbols to which the signal measuredby the terminal is transmitted, compares and determine the number of thebeam of the first information for forming the beam and the number of theslots or symbols to which the signal measured by the terminal istransmitted, wherein the controller determines to change to the secondinformation for forming the beam including information on a smallernumber of beams than the first information for forming the beam, in casethat the number of beams transmitted according to the first informationfor forming the beam is less than the number of the identified slots. 4.The terminal of claim 3, wherein the controller: identifies a beamconfigured to receive a physical downlink control channel (PDCCH) and aphysical downlink shared channel (PDSCH), based on the received RRCsignaling, and determines whether to change the first information forforming the beam to the second information for forming the beam, basedon the beam configured for the PDCCH and the PDSCH.